Omron XTRADRIVE

XtraDrive User Manual Chapter 5: Parameter Settings and Functions
5-91
5.9. Configuration of Serial Commands for AB Encoders
5.9.1. Position Control
5.9.1.1. Defining User Units for Motion Profiles
XtraDrive’s built-in programming capability enables the user to define
various motion profiles without the need for an external motion
controller. Having first defined the relationship between the actual
encoder resolution and the units employed, the user uses units such as
radians, millimeters, etc. to write motion commands. These user units
(aka Engineering Units) are automatically converted by XtraDrive to
encoder units.
Each user unit is comprised of three different factors: Position units,
Speed units and Acceleration units, where each factor has both a
numerator and a denominator.
5.9.1.2. Position Units
Use the following parameters to convert position units from
[Encoder counts] to [User units]:
Parameter Setting
Default
Setting
Signal
Pn2B0 Setting range 1-65535 1 Position units ratio numerator
Pn2B1 Setting range 0-16383 0
Position units ratio numerator
(high bits*)
Pn2B2 Setting range 1-65535 1 Position units ratio denominator
Pn2B3 Setting range 0-16383 0
Position units ratio denominator
(high bits*)
Position user units are calculated according to the formula:
[][]
atordenoratiounitsPosition
numeratorratiounitsPosition
countsUUnitPositionUser
min
1
==
U – The number of encoder counts in each user position unit.
The number need not be an integer.
The maximum value of numerator (Pn2B0) or denominator (Pn2B2) is
65535. In cases where greater values are required, it is possible to use
parameters Pn2B1 and Pn2B3 for storing the high bits of numerator and
denominator, respectively, according to the following formula:
65536
65536
⋅−=
==
HBNBitsLow
N
ofpartIntegerHBBitsHigh
where N - required value.